Activation of Silicon- and Tin-Carbon Bonds. 1,1-Carboboration of Alkynylsilanes and -stannanes

Abstract

amino) the analogous reactions lead mainly to stannoles or alternatively to 1-stanna-4-bora-cyclohexa-2,5-diene derivatives, depending in a complex way on substitutents R at boron and R 1 at the CC bond. The high reactivity of the Sn-C bonds allows the reactions to be conducted under mild conditions enabling the isolation and structural characterisation of intermediates. These possess a zwitterionic structure, in which typically an almost trigonal planar surrounded tin atom is side-on coordinated to the CC bond of an alknylborate unit. Extending these reaction principles to